Artificial N2 fixation to NH3 by electrocatalytic Ru NPs at low overpotential.

Ammonia synthesis, one of the most challenging chemical synthesis processes, plays a vital role in the development of human industry and agriculture. Compared with the industrial Harber-Bosch ammonia process with huge energy input and high CO2 emissions, the search for a resource-saving, environmentally-friendly ammonia synthesis alternative is extremely urgent. Electrocatalytic nitrogen reduction appears to be a good candidate. In this communication, we report the development of ruthenium nanoparticles as a highly efficient and durable nitrogen reduction reaction (NRR) electrocatalyst in acidic electrolyte under ambient conditions. Such electrochemical NRR catalyst exhibits a large NH3 formation rate (24.88 µg h-1 mg-1 cat.) with Faradaic efficiency (0.35%) at -0.15 V versus reversible hydrogen electrode, outperforming many reported NRR electrocatalysts. Note that it exhibits high durability and stability during the entire electrochemical NRR process.

Anchoring Au(111) on a Bismuth Sulfide Nanorod: Boosting the Artificial Electrocatalytic Nitrogen Reduction Reaction under Ambient Conditions.

Electrocatalytic nitrogen reduction reaction (NRR), as a green and sustainable method for ammonia synthesis, has become one of the candidates to substitute industrial Haber-Bosch ammonia synthesis in the near future. In this work, gold nanoparticles (Au NPs) were successfully anchored on bismuth sulfide nanorods (Bi2S3 NRs), which acted as highly efficient electrocatalytic NRR catalysts. The N-philic nature of Bi and the unique mutual coordination of Au-S-Bi can greatly promote the nitrogen adsorption and form the intermediate product N2H*, achieving a boosted improvement in the NRR activity through a continuous hydrogenation reaction. Definitely, the as-synthesized Au(111)@Bi2S3 nanorod catalyst exhibits an excellent NH3 generation rate of 45.57 µg h-1 mgcat.-1 with a faradic efficiency of 3.10% at -0.8 V vs reversible hydrogen electrode. High stability and reproducibility are also demonstrated throughout the electrocatalytic NRR process. Density functional theory calculations were performed to further understand the NRR catalytic mechanism on the Au(111)@Bi2S3 nanorods catalyst.